Site-Specific Allometric Equations for Biomass Prediction of Moringa oleifera Lam. in the Northern Zone of Cameroon

Abstract

Aims: Moringa oleifera is a species with multivariate uses. Despite its socio-economic importance in the northern part of Cameroon, it remains undervalued. Understanding its contribution to the fight against climate change requires precise quantification of its biomass. However, there is a lack of site-specific allometric equations for estimating this biomass. The development of site-specific allometric equations of M.oleifera is therefore imperative to facilitate this effort.
 Study Design: To achieve this objective, a sample of fourteen trees of M.oleifera was taken in from the two areas and divided into diameter classes between 5 and 13 cm.
 Place and Duration of Study: Sample: Agroecological zones of High guinean savannahs and Sudano-sahelian zone of Cameroon between April and July 2021.
 Methodology: The diameter at breast height of these trees and their height were measured. After tree cutting, biomass of compartments of leaves, branches, trunks and roots were determined after drying and weighing. Various allometric equations between biomasses and two parameters of the tree (the diameter and the height) were tested. The adjusted coefficient of determination (R2adj), the residual standard error (RSE) and the Akaike Information Criteria were used for choosing the best models. 
 Results: The different analyses showed that diameter at breast height (DBH) is the variable that offers the best correlation for global above-ground (AGB) and below-ground (BGB) biomass in contrast to the other compartments. Thus, the best models for predicting total above-ground biomass of M. oleifera are -3.653-0.250lnD+5.119lnH (Sudano-Sahelian), -3.916 + 2.982lnD (High guinean Savannahs), -2.340 + 2.117lnD (Global) and finally for roots -6.426 + 2.182lnD.
 Conclusion: These mathematical models could help in estimating the biomass of Moringa oleifera in agroforestry systems under the ecological conditions of Cameroon.